126 REPOET OF COMMISSIONEE OF FISH AND FISHERIES. 



menced to use nets during the spawning-season, by wliicli this entire race 

 of herrings was caught; and since that time fishing has entirely ceased 

 in those places. Similar instances might be gi^'en from many other 

 places on the Baltic. With these experiences fresh in our remembrance 

 it will be evident to every one how important it is to carry on the fisheries 

 in accordance with certain well-defined rules based on a thorough knowl- 

 edge of the nature and mode of hfe of the fish, if the future of the fish- 

 eries is not to be seriously endangered. 



To enable the fisherman to judge for himself what is best for the im- 

 provement of the herring-fisheries in every case, besides those rules 

 which may jiossibly have been laid down by a law of the state, it will be 

 necessary to give some further information regarding the nature and 

 mode of Hfe of the herring. 



Natural history of the herrinf/. — The herring is a gregarious fish and 

 is generally found in large schools, especially at the time when it 

 approaches the coast, which it does regularly at certain seasons of the 

 year, partly to spawn and partly to seek food in calmer waters both 

 before and after the spawning-season. 



During winter the herring lives in the deep water outside those coasts 

 on which it has its spawning-places ; but even during this time it visits 

 the deep fiords, and therefore moves about in the same way as during 

 summer, which is shown by the fact that in the Baltic herrings may be 

 caught diu-ing the winter with nets placed under the ice at difierent 

 depths (from 5 to 24 fathoms), and even with drag-nets in bays and inlets. 

 During its migrations to and from the coast as well as durmg its stay in 

 the deep waters of the open sea, the herring is sometimes near the sur- 

 face and at other times near the bottom ; and these changes of place are 

 thought to depend partly on the temperature of the water and partly 

 on the currents and other natural causes, concerning which, however, 

 experience has not yet taught us such certain lessons as to draw from 

 them reliable conclusions regarding the depth at which the herring is 

 found at dift'erent seasons of the year. Fishermen had, therefore, best 

 make exijeriments by setting nets at different depths. 



The spawning-season varies among the herrings found in one and the 

 same sea, and even the different schools or tribes have different spawn- 

 ing-seasons, and even in one and the same school all fish do not spawn 

 at the same time, probably owing to diflerence of age or to slower or 

 more rapid growth, &c. 



In the Baltic the herring spawns either in spring or in summer, and is 

 accordingly called either spring herring or summer herring. In the 

 Southern Baltic the herrings continue to spawn till the middle of Octo- 

 ber, whilst in the northern portions of this sea the spawning-season 

 closes in August. The fish spawn either outside the coast on raised bot- 

 toms at a depth of 13 to 15 fathoms, or in the bays running inland, mostly 

 in places where the bottom is overgrown with algse. The spawning is 

 done very quickly, as soon as the school has gathered in its spawning- 



